Wooden pulley



IINTTED STATES PATENT Truce.

WALLACE ITI. DODGE, OF MISIIAVAKA, INDIANA.

WOODEN PULLEY.'

SPECIFICATION forming part of Letters Patent No. 368,820, dated August23, 1887. Application filed November 19, 1886. Serial Ilo. 219,417. (Nomodel.)

To a/ZZ whom it may concern:

Be it known that I, WALLACE H. Dono-E, of Mishawaka, iu the county ofSt. Joseph and State of Indiana, have invented new and usefulImprovementsin Vooden Pulleys; and I do hereby declare that thefollowing is a full and accurate description of the same.

In Letters Patent granted to me August 3l, 1886, numbered 318,269,awooden pulley-rim with metallic arms or spokes is shown and claimed.The exterior ends of said spokes are provided with projections whichenter notches or recesses in the pulley-rim, and the intervening spaceis lled with `some solidifying plastic, of which melted sulphur ismentioned as appropriate. While in that case a proper form of notch andentering arm are shown and a proper plastic filling is described, itdiffers from my present invention in this: the rim being of Wood and thearm being of metal, there cannot be any effective adhesion establishedbetween the rim and metal arm, and the whole duty of jointure comes uponthe plastic filling, which in that case serves simply as a packing.

In Letters Patent issued to me as assignee of Charles McNeal, October19, 1886, No. 351,064, a pulley with Wooden rim and Wooden arms orspokes is shown and described. rIhe spokes have dovetailed tenons at theends, and these fit into dovetailed notches in the rim, and are gluedtherein, solid Contact being secured by a wooden wedge driven in at theside of the tenon. Invthis case contact and adhesion are secured at thesides of the tenon; but it is practically very difficult to obtain anyadequate contact and adhesion at the end of the tenon, and there is,therefore, always between the end surface of the tenon and the opposingsurface of the notch a space not filled, or not adeqately Iilled, andthis spot constitutes a weak place in the pullcy-rim. However solid theadhesion at the sides of the tenon may have been originally, thepulley-rim, if unsupported opposite the end of the pulley-arm, may,under heavy service, finally become loose and disabled. rIlhis placecannot safely be iilled by a wedge, because of the liability of drivingthe rim outward from its proper position.

My invention, therefore, improves the pulley with wooden arms and woodenrim by securing in the joint perfect contactand adhesion at the sides ofthe tenon and complete support of the rim over the end of the tenon; andit consists in a wooden rim and wooden arms united by a dovetailed tenonand correspending notch firmly glued together as to the sides and thespace at the end of the tenon filled with some suitable solidifyingplastic.

In the accompanying drawings, Figure l is a perspective view of apulley, partly in section, made in accordance with my invention. Fig. 2is a plan of the same. Fig. 3 is a plan representing` a modification.

A is the pulley-rim, built up7 or otherwise constructed in propermanner. The dovetailed or otherwise undercutnotch b is cut with a propertool. In practice I have marked out the same by means of a templet, andhave then cut them with a band-saw. Any other proper and convenient Waymay be employed, however. The pulley arm or spoke c has cut upon its-enda dovetailed tenon, d, adapted to fit the angles of the notch I), and,with a shoulder, e, to rest upon the interior surface of the rim A. Ipurposely cut the tenon somewhat shorter than the depth of the notch toleave a little space for free admission of the plastic iilling g, and Iprefer, also, to cut away the side of the tenon, as at lt, to permitsaid filling to flow in behind said tenon also, as shown. The thicknessof the arm should be such that the notch will be fully'filled by it atthe plane of the interior surface of the rim. XVhen the tenon d isinserted in the notch b, the inclined surfaces are firmly cemented,preferably with glue, and may be forced into close contact by a wedge,i, or otherwise, if preferred, and said Wedge may be temporarily used,or may also be glued in and suffered to remain, as preferred. My ownpreference is to make the wedge permanent by gluing it in, as therebyclose and sound adhesion may be obtained on both sides of the tenon. Inpractice, and as a precautionary measure, the nails N are also driventhrough the end of the arm c into the rim; but the metallic fasteningswhich may be employed about the pulley do not enter into contemplationand are not concerned in the subject-matter herein claimed.

Subsequently the space around the end of the tenon is filled withsolidifying plastic ma- IOO terial, melted sulphur being preferred. Thusthe arm or spokes are firmly embedded in the rim and solidly joined tothe material of the same, and the joint is made solid by having allinterstices between surfaces not in contact filled with a solid mattercapable of preventing all yielding under any service suitable for thepulley.

Heretofore the adjoining ends of the separated rim of a separable pulleyhave been provided with interlocking surfaces, usually formed bysevering the pulley-rim on an irregular line, as shown in theabove-mentioned patent, 351,064. It is not always convenient to severthe rim in that way, especiallyin pulleys of very large size, and tosubstitute doWels is not satisfactory, as they must necessarily be smallin proportion to the size of the rim, and besides require very nicemeasurements in locating them. Io avoid the difficulties mentioned, Isever the pulley-rim with a straight cut, and then cut transversely inthe severed ends grooves 7c m. This is easy to do, because they can bemarked in exact accordance on the outside while the parts of the rim arein contact. I then fit the tongucp and glue it in one of said grooves.

It will be understood that subsequent to the operations hereinbeforedetailed the face width of the pulley is increased by the additionofwooden rings g to the sides of the rim A, and that said rings Q coverand conceal the notch b and tenon d, together with the filling g andWedge i, and that they thereby also restrain and render impossible anytendency to lateral movement of the arm c inthe rim A When the parts areclamped and bound together by the tension-bolts S.

Having described my invention, I claim- 1. A pulley-rim, A, provided inits inner periphery with dovetail notches b at opposite sides of saidrim as to the center, and a spokearm, c, having a dovetail tenon, d, oneach end, adapted to enter said notches b, said arm being provided witha shoulder, e, at the base of each tenon, to rest against the innersurface of the rim, combined With means for forcing one side of saidtenon hard against one side of said notch while being glued thereto, anda solidifying plastic lling, g, to fill all the partsl of said notch notoccupied by said tenon, as set forth.

2. The pulley-rim A, provided 'with the notch b, and the pulley-arm c,provided with the tenon d, corresponding in shape with the notch b, thesurfaces on one side brought into close contact and caused to adhere bycement, combined With a Wedge, i, also cemented in place, and thesolidifying plastic lling g, substantially as set forth.

WALLACE H. DODGE.

Witnesses:

GHAs. ENDLICH, W. B. I-Iosronn.

